• Korean Journal of Computational Design and Engineering
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• v.19 no.4
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• pp.356-367
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• 2014

A robotic sapatial augmented reality (RSAR) system, which combines robotic components with projector-based AR technique, is unique in its ability to expand the user interaction area by dynamically changing the position and orientation of a projector-camera unit (PCU). For a moving PCU mounted on a conventional robotic device, we can compute its extrinsic parameters using a robot kinematics method assuming a link and joint geometry is available. In a RSAR system based on user-created robot (UCR), however, it is difficult to calibrate or measure the geometric configuration, which limits to apply a conventional kinematics method. In this paper, we propose a data-driven kinematics control method for a UCR-based RSAR system. The proposed method utilized a pre-sampled data set of camera calibration acquired at sufficient instances of kinematics configurations in fixed joint domains. Then, the sampled set is compactly represented as a set of B-spline surfaces. The proposed method have merits in two folds. First, it does not require any kinematics model such as a link length or joint orientation. Secondly, the computation is simple since it just evaluates a several polynomials rather than relying on Jacobian computation. We describe the proposed method and demonstrates the results for an experimental RSAR system with a PCU on a simple pan-tilt arm.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.772-775
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• 1997

A high speed tracking control for 6-6 Stewart platform manipulator is performed by employing the joint-axis sliding mode control based on dynamics. Because of the complex dynamics and kinematics of Stewart platform manipulator, two computer systems, consisting of a PC and a DSP, are adopted, so that real time tasks are run in synchronous and asynchronous modes. It is experimentally proven that the proposed control system leads to an easy to implement and effective control task, and it can achieve the high performance tracking control under the high speed and severe payload condition.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.23 no.6 s.165
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• pp.903-911
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• 1999

A high speed tracking control system for 6-6 Stewart platform manipulator is designed for performing the model based joint-axis sliding mode control. Because of the complex dynamics and kinematics of the Stewart platform manipulator, two computer systems, consisting of a PC and a DSP, are adopted, so that real time tasks are run in synchronous and asynchronous modes. It is experimentally proven that the proposed control system makes the convenience in implementation of model based tracking control, so that it can achieve effective tracking control under relatively high speed and additional payload conditions.

• 제어로봇시스템학회:학술대회논문집
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• 1993.10a
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• pp.654-659
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• 1993

In this paper, a robot controller that has a real time-multitasking OS (Operating System) is developed. It can do given jobs in realtime, so its effectiveness is increased. The controller has several CPU boards, and it is needed to communicate among these boards. For that reason, it is adopted VME bus system and VMEexec OS that can process multiprocess in realtime. Multiprocess includes robot language edit process, vision process, low level motion control process, and teach process in higher layer. And dynamics, kinematics, and inverse kinematics that require realtime calculation are included in lower layer.

• 제어로봇시스템학회:학술대회논문집
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• 1992.10a
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• pp.254-259
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• 1992

In this paper, we propose an optimal method for the tracking a trajectory of the end-effector of flexible robot arms with multiple joints. The proposed method finds joint trajectories and joint torques necessary to produce the desired end-effector motion of flexible manipulator. In inverse kinematics, optimized joint trajectories are computed from elastic equations. In inverse dynamics, joint torques are obtained from the joint equations by using the optimized joint trajectories. The equations of motion using finite element method and virtual work principle are employed. Optimal control is applied to optimize joint trajectories which are computed in inverse kinematics. The simulation of flexible planner manipulator is presented.

• Journal of Institute of Control, Robotics and Systems
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• v.4 no.6
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• pp.780-785
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• 1998

In this paper, it is shown that the conventional methods for dealing with the singularity problem of a manipulator can be generalized as a local minimization problem with differently weighted objective functions. A new damping method proposed in this article automatically determines the damping amounts for singular values, which are inversely proportional to the magnitude of the singular values. Furthermore, this can be done without explicitly computing the singular values. The proposed method can be applied to all the manipulators with revolute joints.

• International Journal of Control, Automation, and Systems
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• v.1 no.3
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• pp.376-384
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• 2003

In this paper, the simple geometric kinematics of a three-wheeled holonomic mobile robot is proposed. Wheel architecture is developed for the holonomic mobile platform in order to provide omni-directional motions by three individually driven and steered wheels. Three types of basic motions are proposed for the path generation of the developed mobile robot. All paths of the mobile robot can be achieved through a combination of the proposed basic motion trajectories. The proposed method is verified through computer simulations and the developed mobile robot.

• Journal of Institute of Control, Robotics and Systems
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• v.19 no.1
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• pp.40-44
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• 2013

The ball-shaped mobile robot, so called ballbot has single point contact on ground and low energy consumption in motion because of the reduced friction. In this paper, a new ballbot is presented, which has omnidirectional mobile platform inside of it as a driving system. Thus the ballbat has omnidirectional mobility without nonholonomic constraints. Kinematics and inverse kinematics of the ballbat is derived also in this paper.

• Transactions on Control, Automation and Systems Engineering
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• v.4 no.3
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• pp.217-223
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• 2002

The paper presents a single constraint equation of the direct kinematic solution of 6-dof (Stewart-Gough) platforms. Many research works have presented a single polynomial of the direct kinematics for several 6-dof platforms. However, the formulation of the polynomial has potential problems such as complicated formulation procedures and discrimination of the actual solution from all roots. This results in heavy computational burden and time-consuming task. Thus, to overcome these problems, we use a new formulation approach, called the Tetrahedron Approach, to easily derive a single constraint equation, not a polynomial one, of the direct kinematics and use two well-known numerical iterative methods to find the solution of the single constraint equation. Their performance and characteristics are investigated through a series of simulation.

• Journal of Institute of Control, Robotics and Systems
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• v.3 no.5
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• pp.469-475
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• 1997

A method for solving the inverse kinematic problem of reclaimer is presented in this paper. The reclaimers in the raw yard are being used to dig raws and transfer them to the blast furnaces. The kinematic configuration of the reclaimer is different from that of commercially available robots, because it has a rotating disk with several buckets at the end of the boom to dig raws. The reclaimer has a redundancy due to the rotating disk : the degrees of freedom are greater than the number of forward kinematic equations. A plane equation in the 3-dimensional space is determined by using several points adjacent to the reclaiming point of the raw ores pile. A constraint is obtained from the relation ship of the plane equation and trajectories of the bucket of the reclaimer. Finally, a solution of the inverse kinematics of the reclaimer is determined by a numerical method.